LSM Hook to key_create_or_update. The LSM hook will call_int_hook
IMA function ima_post_key_create_or_update.
Signed-off-by: Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx>
---
certs/system_keyring.c | 14 ++++++++++++++
include/keys/system_keyring.h | 2 ++
include/linux/lsm_hooks.h | 15 +++++++++++++++
include/linux/security.h | 12 ++++++++++++
security/keys/key.c | 12 ++++++++++++
security/security.c | 14 ++++++++++++++
6 files changed, 69 insertions(+)
diff --git a/certs/system_keyring.c b/certs/system_keyring.c
index 1eba08a1af82..bed19a2f5dd1 100644
--- a/certs/system_keyring.c
+++ b/certs/system_keyring.c
@@ -283,3 +283,17 @@ void __init set_platform_trusted_keys(struct key *keyring)
platform_trusted_keys = keyring;
}
#endif
+
+bool is_builtin_or_secondary_trusted_keyring(struct key *keyring)
+{
+ bool trustedkeyring;
+
+ trustedkeyring = (keyring == builtin_trusted_keys);
+
+ #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
+ if (!trustedkeyring)
+ trustedkeyring = (keyring == secondary_trusted_keys);
+ #endif
+
+ return trustedkeyring;
+}
diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h
index c1a96fdf598b..eb7aa81ec5d3 100644
--- a/include/keys/system_keyring.h
+++ b/include/keys/system_keyring.h
@@ -66,4 +66,6 @@ static inline void set_platform_trusted_keys(struct key *keyring)
}
#endif
+extern bool is_builtin_or_secondary_trusted_keyring(struct key *keyring);
+
#endif /* _KEYS_SYSTEM_KEYRING_H */
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index df1318d85f7d..d447ee689910 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1066,6 +1066,16 @@
*
* Security hooks affecting all Key Management operations
*
+ * @key_create_or_update:
+ * Notification of key create or update.
+ * @keyring points to the keyring to which the key belongs
+ * @key points to the key being created or updated
+ * @cred current cred
+ * @flags is the allocation flags
+ * @builtin_or_secondary flag indicating whether
+ * the keyring to which the key belongs is the builtin
+ * or secondary trusted keys keyring
+ * Return 0 if permission is granted, -ve error otherwise.
* @key_alloc:
* Permit allocation of a key and assign security data. Note that key does
* not have a serial number assigned at this point.
@@ -1781,6 +1791,10 @@ union security_list_options {
/* key management security hooks */
#ifdef CONFIG_KEYS
+ int (*key_create_or_update)(struct key *keyring, struct key *key,
+ const struct cred *cred,
+ unsigned long flags,
+ bool builtin_or_secondary);
int (*key_alloc)(struct key *key, const struct cred *cred,
unsigned long flags);
void (*key_free)(struct key *key);
@@ -2026,6 +2040,7 @@ struct security_hook_heads {
struct hlist_head xfrm_decode_session;
#endif /* CONFIG_SECURITY_NETWORK_XFRM */
#ifdef CONFIG_KEYS
+ struct hlist_head key_create_or_update;
struct hlist_head key_alloc;
struct hlist_head key_free;
struct hlist_head key_permission;
diff --git a/include/linux/security.h b/include/linux/security.h
index 5f7441abbf42..0db4316e236e 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1672,6 +1672,10 @@ static inline int security_path_chroot(const struct path *path)
#ifdef CONFIG_KEYS
#ifdef CONFIG_SECURITY
+int security_key_create_or_update(struct key *keyring, struct key *key,
+ const struct cred *cred,
+ unsigned long flags,
+ bool builtin_or_secondary);
int security_key_alloc(struct key *key, const struct cred *cred, unsigned long flags);
void security_key_free(struct key *key);
int security_key_permission(key_ref_t key_ref,
@@ -1680,6 +1684,14 @@ int security_key_getsecurity(struct key *key, char **_buffer);
#else
+int security_key_create_or_update(struct key *keyring, struct key *key,
+ const struct cred *cred,
+ unsigned long flags,
+ bool builtin_or_secondary)
+{
+ return 0;
+}
+
static inline int security_key_alloc(struct key *key,
const struct cred *cred,
unsigned long flags)
diff --git a/security/keys/key.c b/security/keys/key.c
index 764f4c57913e..973dfead490c 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -14,6 +14,7 @@
#include <linux/workqueue.h>
#include <linux/random.h>
#include <linux/err.h>
+#include <keys/system_keyring.h>
#include "internal.h"
struct kmem_cache *key_jar;
@@ -823,6 +824,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
key_ref_t key_ref;
int ret;
struct key_restriction *restrict_link = NULL;
+ bool trusted_keyring = false;
/* look up the key type to see if it's one of the registered kernel
* types */
@@ -936,6 +938,16 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
goto error_link_end;
}
+ /* let the security module know about the key */
+ trusted_keyring = is_builtin_or_secondary_trusted_keyring(keyring);
+ ret = security_key_create_or_update(keyring, key, cred, flags,
+ trusted_keyring);
+ if (ret < 0) {
+ key_put(key);
+ key_ref = ERR_PTR(ret);
+ goto error_link_end;
+ }
+
key_ref = make_key_ref(key, is_key_possessed(keyring_ref));
error_link_end:
diff --git a/security/security.c b/security/security.c
index 250ee2d76406..df6f561e4418 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2280,6 +2280,20 @@ EXPORT_SYMBOL(security_skb_classify_flow);
#ifdef CONFIG_KEYS
+int security_key_create_or_update(struct key *keyring, struct key *key,
+ const struct cred *cred,
+ unsigned long flags,
+ bool builtin_or_secondary)
+{
+ int rc = call_int_hook(key_create_or_update, 0,
+ keyring, key, cred, flags,
+ builtin_or_secondary);
+ if (rc)
+ return rc;
+ return ima_post_key_create_or_update(keyring, key,
+ builtin_or_secondary);
+}
+
int security_key_alloc(struct key *key, const struct cred *cred,
unsigned long flags)
{
--
2.17.1
